OPA388_17 Datasheet, PDF (20/34 Pages) Texas Instruments – Precision, Zero-Drift, Zero-Crossover, True Rail-to-Rail Input/Output, Operational Amplifiers

OPA388, OPA2388, OPA4388
SBOS777 – DECEMBER 2016
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Typical Application (continued)
The resistor value selected for R₁ and R₃ was 1 kΩ. 15.4 kΩ was selected for R₂ and R₄ because this number is
the nearest standard value. Therefore, the ideal gain of the difference amplifier is 15.4 V/V.
The gain error of the circuit primarily depends on R₁ through R₄. As a result of this dependence, 0.1% resistors
were selected. This configuration reduces the likelihood that the design requires a two-point calibration. A simple
one-point calibration, if desired, removes the offset errors introduced by the 0.5% resistors.
8.2.3 Application Curve
3.30
1.65
0
-1.0
-0.5
0
0.5
1.0
Input Current (A)
Figure 42. Bidirectional Current-Sensing Circuit Performance:
Output Voltage vs Input Current
8.3 System Examples
8.3.1 Single Operational Amplifier Bridge Amplifier
Figure 43 shows the basic configuration for a bridge amplifier.
VEX
R1
R
R
+5V
R
R
VOUT
VREF
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Figure 43. Single Operational Amplifier Bridge Amplifier Schematic
20
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